Content-Type

Both directions

Declares the media type and charset; get it wrong and an image shows up as text.

On the wireContent-Type: …
CategoryBoth directions

Headers that can appear on either side.

How to read this

  • The first digit of a status code carries the meaning: 4 means the request, 5 means the server.
  • 404 means "not there"; 403 means "there, but not for you". Swapping them makes debugging slower.
  • Header names are case-insensitive — Content-Type and content-type are the same header.
  • Caching and CORS problems usually come down to one header line, visible in the browser’s network tab.

Frequently asked questions

Q. What does HTTP Content-Type mean?

Declares the media type and charset; get it wrong and an image shows up as text.

Q. What does Content-Type look like on the wire?

It travels as Content-Type: …

Q. Where does Content-Type appear?

In both directions.

Q. What group does Content-Type belong to?

The both directions group; the rest of that group is listed further down.

Same group

Reference docs